Have magnets on your fridge

For eternity: how long do magnets last?

The durability or: three enemies of magnets

As fascinating as the magnetic effect is - unfortunately it is even with permanent magnets not forever. Because even if you might not expect that: Magnets do not lose their power with time. Unless that three enemies of the magnet strike.

vibration

Neodymium magnets are opposite to shocks insensitive. For all others Permanent magnets holds that Avoid vibrations at all costs should be. Depending on how strong the magnetic force was, it is enough for the magnet to work once falls downto mess up his order. Thereby its magnetic force decreases or is completely destroyed. The more often the magnet is shaken, the lower its magnetic property towards the outside.

temperature

Every magnet has a so-called Curie temperature, which is the maximum operating temperature describes. Especially the super strong ones Neodymium magnets are susceptible to this and lose their magnetic power already at 80 ° C. However, this limit can be increased to 200 ° C with various additives. Also cold can ensure that the internal order messed up is brought and thus the force is less. That's why they should recommended temperatures must be strictly observed.

Magnetic fields

Once order has been established, it can of course also destroy it again. A strong one external magnetic field (or several) can lead to the uniformity Re-mix the aligned particles and thus its power no longer appears to the outside world.

The boss for magnets

Indeed, magnets can act in front of their three enemies correct storage and use be well protected, which should not actually reduce their magnetic force. However, there is one factor that can kill even the strongest magnet: the time or the decomposition, corrosion, So rust is probably the only thing that really matters permanently destroy a magnet can.

To protect the material from oxidation, one adds certain substances (e.g. cobalt) added during production. In addition, the magnets are then still with a layer from for example nickel or Epoxy resin overdrawn. If this is not damaged, a magnet will definitely retain its force for a very long time.

Just in case

And even if a magnet is demagnetized, it still loses not the abilityto act magnetically. All that needs to be done is to restore its order by exposing it to a strong magnetic field. As long as that material so not chemically decomposed has is that durability the magnetic force actually almost unlimited - even if it is not always visible to us.

swell

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